The Colorado pikeminnow, also known as the Colorado squawfish, is the largest North American minnow. These fish have been known to reach six feet in length and 80 pounds in weight. Adult fish may be green-gray to bronze on their backs and silver to white along their sides and bottoms. During spawning, their fins can take on an orange hue.
Range: Historically, the pikeminnow occurred in great numbers throughout the Colorado River system from Green River in Wyoming to the Gulf of California in Mexico. In Colorado, they are currently found in the Green, Yampa, White, Colorado, Gunnison, San Juan, and Dolores rivers.
Habitat: The Colorado pikeminnow thrives in swift flowing muddy rivers with quiet, warm backwaters.
Diet: Colorado pikeminnow are primarily piscivorous (fish-eaters), but smaller individuals also eat insects and other invertebrates.
Reproduction: The species spawns during the spring and summer over riffle areas with gravel or cobble substrate. Eggs are randomly splayed onto the bottom and usually hatch in less than one week.
Endangered status: The Colorado pikeminnow is listed as threatened in Colorado and endangered federally. Dam construction and other water diversion projects along the Colorado River system has contributed to its decline. Dams lower water temperatures and block migration routes, hampering spawning of pikeminnow. The introduction of non-native bait minnows and stocking of predatory game fish species (such as northern pike, largemouth bass, sunfish, and catfish) are suspected to have contributed to their decline as well. Recovery actions are underway to remove non-native fish, construct bypasses around in-stream barriers, and restock pikeminnow into native habitat.
For more information, see the Natural Diversity Information Source species profile.